Endoparasites and Epibionts of Loggerhead and Green Sea Turtles From the Eastern Mediterranean, Turkey: a Detailed Assessment

Abstract

Two species of sea turtles, the loggerhead (Caretta caretta) and the green turtle (Chelonia mydas), use Turkey's Mediterranean and rarely Aegean Sea coasts for nesting and foraging. The injured sea turtles are regularly transferred for treatment to the Sea Turtle Research, Rescue and Rehabilitation Center (DEKAMER) Muğla Ortaca-Dalyan (Turkey) from the different coasts of the these two seas-these include Çanakkale, Balıkesir, İzmir and Aydın (Aegean Sea); Antalya and Mersin (Mediterranean Sea) and also Muğla (it has two coasts both Aegean Sea and Mediterranean Sea). In this study, both internal and external parasites and epibiont species of turtles that died during treatment were examined. This is the first detailed parasitological and epibiont study on these sea turtles in the Turkish coast. Twenty-two adult Caretta caretta and twelve green turtles were examined and these symbiotic groups were recorded: endoparasitic digeneans and nematodes, and epibiotic annelids and cirripeds (barnacles). The observed three digenean species (Pyelosomum renicapite, Learedius learedi and Deuterobaris proteus) are recorded in Turkey for the first time. Also, Ch. mydas and C. caretta represent new host records for these digenean species in Turkey. Ch. mydas represents a new host record for two cirriped species (Chelonibia testudinaria and Lepas hillii) from Turkey and C. caretta also represent a new host record for Ozobranchus margoi from Turkey. Based on the available literature, the implications of these symbionts on sea turtle health are discussed, highlighting the importance of recording parasitic data of sea turtles. The study of internal and external parasites is very important, especially for the treatment of sea turtles under rehabilitation. © 2025 Sciendo. All rights reserved.